1. Field of the Invention
The field of this invention lies within the self contained breathing gas apparatus art. Specifically, it resides within the self contained breathing apparatus art as it relates to systems for regulating and providing breathing gas under pressure within an entire system, utilizing demand regulators, reserve control valves, and pressurized gas tanks. It particularly relates to first stage regulation of gas in combination with a relief valve function attendant therewith in the event the first stage regulator fails.
2. The Prior Art
The prior art related to self contained breathing gas apparatus incorporates the utilization of single and multiple tanks with a conduit between them. The conduit is usually valved so that the breathing gas can escape from the tanks to be regulated by a first stage regulator.
Such first stage regulators incorporate a piston having a sealing surface which dynamically operates inwardly and outwardly, thereby opening and closing a valve port connected thereto which is exposed to high pressure gas. The opening and closing of the valve port allows for the transition of gas from the high pressure tanks to a conduit at intermediate pressure, leading to a demand regulator.
It has been generally accepted practice in the operation of the regulator piston to use a number of springs to bias the piston. In the piston seal it has been customary to incorporate various seals and dynamically sealing O Rings and washers.
This invention incorporates an eliptical cross sectioned O Ring which does not substantially slide within the regulator cavity. To the contrary, the O Ring supports the piston and is deformed across its cross section by the variable pressure as demanded. In other words, upon demand, the O Ring is deformed through its cross section by virtue of a change in spring loading on the piston and allows an openinig of a valve which the piston operates. The O Ring also serves a relief valve function to allow blow-by of excessive intermediate pressure that can be caused by first stage regulator bleeding or failure.
The entire system utilizes a shell or casing that can be opened along a parting line thereof which is secured by a snap buckle arrangement. The tanks of the system, in contradistinction to the prior art, are supported within deformable straps around each respective tank that are secured in turn by bolts to the casing. In contradistinction thereto, the prior art has specifically relied upon a backpack or support plate for the breathing gas tanks to be secured to and carried by. In this invention, the tanks are maintained within a formed casing which is conformed to a user's back and streamlined.
The controls to the system are mounted through the casing. Thus, the valving of the tanks can be controlled by a valve on the exterior of the casing. The filling of the tanks can be provided through a filling tube which can be extended from the casing and attached to a high pressure breathing gas source.
To the contrary, the prior art utilizes a filling manifold attached to a valve which is not easily accessible. The instant invention overcomes the filling problems of the prior art by providing a filling port that is easily accessible and removed from its securement fitting.
A reserve valve mechanism is incorporated within the manifold of the system to provide a warning of when the pressure in the breathing gas tanks drops below a certain level. The reserve valve closes an opening through the reserve system at a pre-established pressure which can then be opened by twisting a reserve knob which opens the valve again, thereby making the reserve supply of air available to the user.
In the prior art, the reserve system is connected to a single tank. The reserve system in the prior art is inaccessible to a user and cannot be relied upon to serve a user effectively. To the contrary, this invention provides an easily accessible reserve valve which serves the function of maintaining a reserve pressure in one tank that can be supplied to the remaining tanks.
The prior art also provides pressure gauge attachments that move freely and as a consequence can be broken off when a diver is swimming. This invention provides a pressure gauge which is incorporated within the entire system and can be attached to one of the straps comprising the harness so that it does not move freely.
As a consequence, the entire casing and system within the casing of this invention is an advance over the art by incorporating a completely unitized system with all the necessary support apparatus therefor. The entire system is carried and utilized as a unit much in the same manner of when people in outer space have an entire life support system incorporated on their back. Thus, this invention is a substantial advance over the prior art as it relates to self contained breathing gas apparatus and life support systems for both terrestial and underwater breathing use.